During the past two decades, technological development related to telecommuni-
cation technologies has allowed organizations of all types and size to be able to de-
velop effective networking applications in support of information management. Fur-
thermore, telecommunication technologies combined with computer technology have
created the foundation of modern information technology which has affected all as-
pects of societal and organizational functions in our modern world.
Emergingmarketshaveseenanunprecedentedgrowthinthelastfewyears.Theoperatorfocus
has been on giving complete coverage to all regions (urban to rural) and to subscription to all –
people from the highest to the lowest income groups. When the idea is taking coverage for
the remotest of the regions and getting the ‘unconnected–connected’, technology and business
modelling are two important focus areas.
The very title of this book is borrowed from the information theory vocabulary,
and, quite naturally, it is an outline of this theory that will serve as an introduction.
The subject of information theory is the scientific study of communications. To this
end it defines a quantitative measurement of the communicated content, i.e. informa-
tion, and deals with two operations essential for communication techniques: source
coding and channel encoding.
The aim of this book, the first of two volumes, is to present selected research that
has been undertaken under COST Action IC0902 ‘‘Cognitive Radio and Net-
working for Cooperative Coexistence of Heterogeneous Wireless Networks’’
(http://newyork.ing.uniroma1.it/IC0902/). COST (European Cooperation in Sci-
ence and Technology) is one of the longest-running European frameworks sup-
porting cooperation among scientists and researchers across Europe.
Optical communication technology has been extensively developed over the
last 50 years, since the proposed idea by Kao and Hockham [1]. However, only
during the last 15 years have the concepts of communication foundation, that
is, the modulation and demodulation techniques, been applied. This is pos-
sible due to processing signals using real and imaginary components in the
baseband in the digital domain. The baseband signals can be recovered from
the optical passband region using polarization and phase diversity tech-
niques, as well as technology that was developed in the mid-1980s.
This thesis is about wireless communication in shared radio spectrum. Its origin and
motivation is ideally represented by the two quotations from above. In this thesis, the
support of Quality-of-Service (QoS) in cognitive radio networks is analyzed. New
approaches to distributed coordination of cognitive radios are developed in different
spectrum sharing scenarios. The Wireless Local Area Network (WLAN) 802.11 proto-
col of the Institute of Electrical and Electronics Engineers (IEEE) (IEEE, 2003) with
its enhancement for QoS support (IEEE, 2005d) is taken as basis. The Medium Access
Control (MAC) of 801.11(e) is modified to realize flexible and dynamic spectrum
assignment within a liberalized regulation framework.
The objective of this book is to allow the reader to predict the received
signal power produced by a particular radio transmitter. The first two
chapters examine propagation in free space for point-to-point and
point-to-area transmission, respectively. This is combined with a dis-
cussion regarding the characteristics of antennas for various purposes. In
chapter 3, the effect of obstacles, whether buildings or mountains, is
discussed and analytical methods, whereby the strength of a signal is the
shadow of an obstacle can be predicted, are presented.
During the past two decades there has been a substantial growth in research in
wireless communications. The number of journals published from various parts of
the world catering to the research community has grown exponentially. Despite
such a growth, the engineering community still needs more information so as to
thoroughly comprehend wireless channel characteristics. What specifically must be
understood are the effects of channel degradation brought on by statistical fluctua-
tions in the channel.
During the past decade, many wireless communication techniques have been
developedto achievevariousgoals suchas higherdata rate,morerobustlink quality,
and higher number of users in a given bandwidth. For wireless communication
systems, depending on the availability of a feedback link, two approaches can be
considered: namely open and closed loop. Open loop communication system that
does not exploit the channel knowledge at the transmitter is now well understood
from both a theoretical and practical point of view.
The writing of this book was prompted by two main developments in wireless
communications in the past decade. First is the huge surge of research activities in
physical-layer wireless communication theory. While this has been a subject of study
since the 60’s, recent developments in the field, such as opportunistic and multi-input
multi-output (MIMO) communication techniques, have brought completely new per-
spectives on how to communicate over wireless channels.
